I used to use an acronym: KWiK (Keys, Wallet, Knife) Have a single place you put things, and put them there as soon as you're at that place. I put a small shel

I used to use an acronym: KWiK (Keys, Wallet, Knife) Have a single place you put things, and put them there as soon as you're at that place. I put a small shelf by the door for the wallet and keys, the knife/multi-tool is an always-carry. Now that I also carry a small flashlight at all times I'm in search of a new acronym, but mostly for completeness--once the habit was built it's almost never a problem anymore. The phone still gets forgotten on occasion, but it's rarely an issue.